1. Field
This invention relates generally to emulsion treaters and, more particularly, to an improved emulsion treater for oil/water emulsion such as oil well production.
2. Prior Art
As will appear from the ensuing description, the present emulsion treater may be utilized to treat a variety of oil/water emulsions. The primary application of the emulsion treater, however, is treating oil well production to recover its oil phase at pipeline specifications. For this reason, the invention will be described in this particular context.
The output from a producing oil well, commonly referred to in the oil refining trade as oil well production or crude, is a gas-bearing emulsion composed of crude oil and impurities in the form of water or brine, entrapped gas and solid matter. An initial step in the crude oil recovery process involves treatment of this emulsion or crude, after virtually all of its free water has been knocked out and so-called finishing additives have been added to the crude, to segregate the impurities from the crude oil and reduce its impurity content, which may initially run as high as 10% or more, to a level such that the crude oil meets so-called pipe line specifications. The apparatus used to accomplish this treatment is referred to as an emulsion treater or emulsion treater tank.
The prior art is replete with a vast assortment of such emulsion treaters, examples of which are described in the following U.S. Pat. Nos. 3,389,536; 3,672,127, 3,312,044, 2,713,919.
The present invention is concerned particularly with oil well emulsion or production treaters of the kind whose emulsion treatment process involves heating the incoming crude to initiate segregation of its gas, crude oil and water phases, additional stratification of the phases by a settling action, and extraction of the segregated oil phase.
The mechanics of this emulsion treatment process and the existing emulsion treaters for carrying out the process are well understood and hence need not be explained in elaborate detail. Suffice it to say that the emulsion treaters comprise an elongate horizontal treater tank into which the crude is introduced, generally at the top of the tank, and then heated. This heating of the crude reduces its viscosity and expands the entrapped gas, thereby causing the production and expansion of gas bubbles which rise to the top of the tank. Release of the entrapped gas from the incoming crude increases its density, whereby the crude gravitates downwardly in the treater tank as it flows through the heating zone of the tank. The reduction in viscosity of the crude produced by heating also initiates segregation or stratification of its oil and water phases, release of solid impurities from the crude, and gravitation of the water and solid impurities to the bottom of the tank.
After heating, additional stratification of the oil and water phases and separation of solid impurities is accomplished by a settling action to provide at the bottom of the tank a layer or stratum of water and solid impurities, above the water a layer or stratum of relatively impurity free crude oil, and above the oil a gas or vapor region.